Clark Howard uses the cheapest razors he can find then cleans and dries them after every use. He claims that he can get a month out of each razor. I tried it and I didn’t get a month but I can get 2 to 3 weeks. He said blades go dull from pitting and rust, not your beard.
Except for the price.
I've been using a DE for a first pass, then using up my supply of multiblades for a second pass. Safer for the more "complicated" areas of the face/neck where the DE would tend to nick or scrape.
I rinse the DE head in a small jar of alcohol, and wipe down the exposed blade edges. Likewise, I just wipe down the multiblades themselves, avoiding the comfort strips.
I try to get a week out of the DE, and a month out of the multiblade.